Landscape and ecosystem health dynamics in response to terrain in southwest China's karst mountains: A study with evidence since 1980

The karst mountainous regions in southwest China have long been a key area for ecological restoration. As an important indicator of environmental quality, ecosystem health plays a crucial role in evaluating the effectiveness of ecological restoration efforts. However, current research lacks a multidimensional perspective that integrates terrain and geology to reveal the evolution of ecological environments in karst mountain regions. This study develops a theoretical framework for the dynamic response mechanism of mountain ecosystem health based on a stepwise research paradigm: “geological background—terrain constraints—land use—landscape pattern—ecosystem health.” Using the mountainous regions of southwest China as a case study, we examined the evolution of landscape patterns and ecosystem health from 1980 to 2020, employing spatial analysis methods. By utilizing a random forest algorithm with a goodness-of-fit of 0.903, we revealed the response mechanisms of ecosystem health to terrain, landscape patterns, and land use. The results showed that landscape pattern evolution under karst geological conditions contributed more to global vegetation greening than in non-karst regions. By 2020, the ecosystem health index had increased to 0.56, with the average healthy area accounting for 48.23 % of the total region. Overall, landscape patterns exhibited trends of diversification and fragmentation. Farmland landscapes shifted toward low-mountain and valley regions, while woodland landscapes expanded in high-mountain and steep-slope areas. Ecosystem health in mountainous regions displayed a three-dimensional pattern of high–low–high. Land use and landscape patterns in mountainous areas significantly influenced ecosystem health. The findings provide a scientific foundation for ecological restoration and the sustainable development of landscapes in karst mountainous regions and other ecologically fragile areas. • Constructed a new research paradigm integrating geology, terrain, landscape, and ecosystem health • Revealed that karst ecological restoration plays a greater role in global greening • Discovered the three-dimensional “high–low–high” distribution pattern of ecosystem health • Quantified land use and terrain as key influencing factors using machine learning • Verified that initiatives such as the Grain-for-Green Program steadily enhance ecological health